Hydraulic motor unit



United States Patent Inventor John T. Parrett Benton Harbor, Michigan Appl. No. 797,635 Filed Feb. 7, 1969 Continuation-impart of Ser. No. 598,340, Dec. 1, 1966, now Patent No. 3,435,774 Patented Nov. 17, 1970 Assignee KoehringCompany a corporation of Wisconsin HYDRAULIC MOTOR UNIT 10 Claims, 2 Drawing Figs.

U.S.Cl 91/501, 91/448 Int. Cl ..F0lb 31/04, F011 3 3/02 50 Field ofSearch 91/175,

l80Cursory. l98Cursory; l03/162Curs0ry [56] References Cited UNITED STATES PATENTS 2,442,125 5/1948 Gunning 91/175 3,155,010 11/1964 Johnsonetal 91/175 Primary Examiner Paul E. Maslousky Attorney-Hofgren, Wegner, Allen, Stellman and McCord ABSTRACT: A hydraulically driven turntable with a base defining a stationary annular cylinder block with axial cylinders therein, the cylinder block being flanked by opposed cam plates fixed with respect to the turntable and reciprocating opposed pistons in the cylinders, there being also provided an annular valving member within the cylinder block having spaced annular manifold passages therein.

Patemed Nov. 17, 1?0

Sheet l or 2 QQN Patented Nov. 17, W70

Sheet HYDRAULIC MOTOR UNIT This application is a continuation in part of my copending application Ser. No. 598,340, filed Dec. 1, 1966, now U.S. Pat. No. 3,435,774, assigned to the assignee or the present application.

This invention relates generally to hydraulic fluid energy translating devices andmore particularly to a hydraulic pump or motor device.

One type of hydraulic fluid energy translating device is an axial piston design in which the pistons reciprocate in cylinders disposed parallel to the axis of rotation on the cylinder block. In one common design ofthis type, rigid pistonsare employed which project from the cylinderblock and engage an inclined cam rnemberwhich serves to reciprocate the pistons.

As the cylinder block rotates relative tothe cam member, the pistons exert a radial load on the cylinder block tending to tilt the block and destroy the sealing engagement between the rotating cylinder block and a stationary valve member through which fluid flows to and from the block. Furthermore, the force of hydraulic fluid in the cylinders acting on the bottoms of the cylinders causesan axial load to be imposed .on the cylinder block which alsodetracts fro nthe performance of the device.

In accordance with the present-invention, a multiple piston hydraulic unitdevice is provided in which all the axial and radial loads on the cylinder block are balanced. This is effected by the use of opposed spherical type pistons in each of the cylinders withseparate cam members, for reciprocating the pistons at one end of thecylindersand at the other end.

It is, therefore, a primary object of the present invention to provide a new and improvedhydraulic fluid energy translating device.

Another objectof thepresent invention is to provide a new and improved hydraulic fluid energy translating device in which all of the axial and radial loads on the cylinder block are balanced.

A further object of the present invention is to provide a new and improved hydraulic fluid energy translating device of the type generally described having spherical balls for pistons eliminating the radial loads on the cylinder block, and further including sealing rings around a portion of the piston for preventing the leakage of hydraulic .fluid around the, piston while still permitting a direct transmittal offorce from the cam through thepiston to the associated cylinderbore.

A still furtherobject of the present invention is to provide a new and improved hydraulic fluid energy translating device of the type described above in which opposed-spherical pistons are provided in each of the cylinders to increase the capacity of the device and eliminate axialloading ofthe cylinderblock.

A further object of the presentginvention isto provide a new and improved hydraulic fluid energy translating ,device ofthe type describedgenerally above mounted directly to rotatea turret in a movablecraneor the like without the necessity of employing any gearing between thedevice and the rotatable turret.

Otherfeatures andadvantages of the invention will be apparent from the followingdescriptionof certain embodiments thereof taken in cqnjunctionwith the accompanying drawings.

FIG. 1 isacrossssectionalelevation of amobile crane turret incorporating the hydraulic fluid energy translating device of the present invention; and

FIG. 2 is a fragmentarysection of anotherembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown inFlG. 1a hydraulic .pumpor motor device 210, is shown driving a rotary turntable 211. Turntable 211 is adapted to support a mastcarrying anarticulated beam derrick on a mobile crane. The motor 210 is controlled by an operator through a manual control valve2l2on the rotatable mast which delivers fluid;underpressure toand from conduits 213 and 214 so that the mast may be rotated as desired.

The turntable 211 is rotatably mounted in an annular support 215 by a heavy duty bearing 216. Support215 is fixed to an annular'base 228 which is adapted to be fixed to the frame of the mobile crane (not shown). The base 228 has an inwardly projecting flange 228' which defines the cylinder block for the motor 210 and has formed therein an annular series of cylinders 237 which receive piston assemblies 245 having spherical balls and sealing rings directly engaging the associated cylinders, identical with those described with reference to FIGS. 1 to 3 inmy parent application, Ser. No. 598,340, now U.S. Pat. No. 3,435,774.

For reciprocating the piston assemblies 245 rotatable cam plates 249 and 252 are provided each having multiple lobe cam tracks 253. Plate 252 is rigidly fixed to turntable 211 by threaded fasteners218. Fasteners 219 fix the lower cam plate 249 to the upper cam plate 252 so that both rotate together with the turntable 211.

For conveying fluid to and from the cylinders 237 an annular valve member 217 isprovided fixed between the cam plates 249 and 252. Valve member 217 has passages 220 and 221 therein communicating respectively with conduits 213 and 214, and ,opening at their other ends to axially spaced areas on the periphery of the valve 217.

Mounted between the valve member 217 and the cylinder block 228' is an annular port member 280 fixed to the valve plates by suitable pins 287. Spacedannular manifold passages 284 and 285 are provided on the inner surface of port member 280 and continuously communicate with passages 220 and 221, respectively. Manifold passage 284 communicates with ports 282 through passages 283, there being one of these passages for each of theports 282. Further, manifold;2 85 continuously communicates with ports 282A through passages 288. The ports 282A are alternately disposed with respect to the ports 282 defining alternate high and low pressure ports disposed about the periphery of valve member 280 so that they serially communicate with cylinders 237 through cylinder ports24l as the valve member rotates.

lnone exemplary construction of the turntable drive shown in FIG. 1, I00 cylinders 237 were provided, each cam 249. 252 had 64 cam lobes, and the portmember 280 had 64 ports 282 and 64 ports 282A.

' In operation of the FIG. 1 embodiment, if the operator ports fluid to conduit 213, ports 282A will be high pressure ports pressurizing the cylinders 237 communicating therewith, and ports 282 will be low pressure ports receiving discharge fluid from the cylinders and conveying it to conduit 214. Rotation of the turntable 211 then begins and the pistons withdrawing from the cylinders and riding down the cam lobes and cam tracks 253 cause rotation ,of the cam plates along with port member 280, valve member 217 and turntable 211. Instead of the cylinder block rotating as in conventional constructions,

. provided for the purpose of pressure balancing the cylinder block defining flange 328.

A turntable 31] (shown only as a fragmentary section in FlG.-2 as are the otherpartsshown in this FIG.) is adapted to support a mast orarticulated beam with motor 310 being controlled by an operator .on the mast in a mannersimilarto the FIG. 1 embodiment.

Turntable 311 is rotatably mounted in annular support members 315 and 315A by a heavy duty bearing assembly 316. A suitable threaded fastener 388 connects the annular supports 315 and 315A together as a unit with an annular base 328 which isadapted to be fixed to the frame of an associate mobile crane so that these parts remain stationary.

For reciprocating the piston assemblies 345 rotatable cam plates 349 and 352 are provided each having multiple lobe cam tracks 353. Plate 352 is rigidly fixed to turntable 311 by threaded fasteners 318. Fasteners 322 fix the lower cam member 349 to a horizontally extending annular plate 323 which is fixed to annular valve member 317 by threaded fasteners 324. Valve member 317 is in turn fixed to the turntable 311 by threaded fasteners 319 so that the turntable, the valve member 317 and the cams 349 and 352 rotate together as a unit.

For conveying fluid to and from the cylinders 337 the annular valve member 317 is provided with passages 320 and 321 therein communicating respectively with conduits 313 and 314, opening at their other ends to axially spaced areas on the periphery ofthe valve 317.

For the purpose ofconveying fluid to and from the cylinders 337 from passages 320 and 321 ports 382 are defined in an annular horizontal surface 326 of the turntable 311 slidably engaging an upper end face 327a of the cylinder block 328. Ports 382 serially communicate with the cylinders 337 as the turntable rotates through axial passages 327 and 341 in the cylinder block, it being understood that there is one set of passages 327 and 341 for each cylinder 337.

Alternate ones of the ports 382 communicate with annular passage 385 in the turntable 311 through axial bores 329 in the turntable, while the remaining alternate ports 382 communicate with annular passage 384 through axial passages 382 in the turntable. Since the passages 384 and 385 are annular in configuration they continuously communicate with the passages 320 and 321 respectively so that valving occurs solely between the surfaces 326 on the turntable and 327a on the cylinder block 328'. As with the FIG. 1 embodiment either conduit 313 or 314 may be a high pressure passage depending upon the desired direction of rotation of the turntable 311.

For the purpose of pressure balancing the cylinder block 328, the pressure balancing plate 387 is provided with a plurality of pockets 388 which correspond in number with the ports 382. Alternate ones of the ports 388 communicate with each other through passages 389 and an annular passage 390. The remaining alternate ports continuously communicate with one another through passages 391 and annular passage 392. The pockets 388 are aligned with ports 382 so that the high pressure ones of the ports 382 pressurize the aligned alternate pockets 388 corresponding thereto without pressurizing the other alternate pockets 388 since they are sealed from one another.

Moreover, since the pockets 388 have an area equal to the ports 382 and are pressurized at the same time, equal and opposite hydraulic forces will be applied to the opposite sides of cylinder block 328' thus pressure balancing the cylinder block. The high fluid pressure in one of the annular passages 390 or 392 serves to urge the pressure plate into engagement with the cylinder block 328.

The operation of the FIG. 2 embodiment is substantially the same as the FIG. 1 embodiment and a repetition thereof is believed unnecessary.

lclaim:

1. A hydraulically driven turntable, comprising: a stationary base member, an annular cylinder block projecting inwardly from said base member and stationary with respect thereto, a plurality of axially disposed cylinders in said block, pistons slidable in said cylinders, an annular turntable having a large opening therethrough, a cam plate of generally annular configuration fixed to said turntable and overlying said cylinders and adapted to reciprocate the pistons in the cylinders, said turntable being coaxial with respect to and adjacent said cylinder block, an annular valving member fixed with respect to said turntable and positioned within said annular cylinder block, said valving member having a plurality of high and low pressure ports in the periphery thereof, a first annular passage in said valving member connecting the high pressure ports, a second annular passage in said valving member connecting the low pressure ports, said valving member having a large substantially unobstructed central opening therethrough, first conduit means extending into said central opening inwardly from said first annular passage for connection with a control valve, and second conduit means extending inwardly from said valve member and communicating with said second annular passage.

2. A hydraulically driven turntable as defined in claim 1, including a second generally annular cam plate fixed with respect to said turntable and underlying said cylinders, said cylinders extending completely through said cylinder block, a second set of pistons in said cylinders in opposed piston fashion, said second set of cylinders being adapted to be reciprocated by said second cam plate, said first and second conduits beingadapted to be connected to said control valve stationary with respect to said turntable whereby the turntable may be operated by an operator supported on the turntable.

3. A hydraulically driven turntable as defined in claim 1, wherein said base member has an annular portion projecting upwardly from said cylinder block, said turntable being mounted within said upwardly projecting portion, axial thrust bearing means between said upwardly projecting portion and said turntable.

4. A hydraulically driven turntable as defined in claim 1, including a manifold member generally annular in configuration mounted within and fixed with respect to said valve member, said manifold member having a large substantially unobstructed central opening and an inlet port and an outlet port opening to the inner periphery thereof, said conduits being connected to said ports, a first generally diagonal passage in said manifold member connecting said inlet port to one of said manifold passages, a second generally diagonal passage in said manifold member connecting said outlet port with the other manifold passage.

5. A hydraulically driven turntable as defined in claim 2, wherein said valve member is mounted between and fixed to said cam plates.

6. A hydraulically driven turntable as defined in claim 1, including opposed piston assemblies in each of said cylinders, each of said piston assemblies including a spherical member directly engaging the associated cylinder, and a sealing ring directly engaging both the cylinder and the associated spherical member.

7. A hydraulically driven turntable comprising: a stationary base member, an annular cylinder block projecting inwardly from said base member and stationary with respect thereto, a plurality of axially disposed cylinders in said cylinder block, pistons slidable in said cylinders, an annular turntable having a large opening therethrough, a cam plate of generally annular configuration fixed to said turntable and overlying said cylinders and adapted to reciprocate the pistons in the cylinders, said turntable being coaxial with respect to and adjacent said cylinder block, an annular valving member fixed with respect to said turntable and positioned to cooperate with said cylinder block, said valving member having inlet and outlet passages therein and a large substantially unobstructed central opening therethrough, a first annular passage communicating with said inlet passage, a second annular passage communicating with said outlet passage, port means serially communicable with said cylinders in said cylinder block, first conduit means connecting said first annular passage with one set of port means, second conduit means connecting said second annular passage with the remaining port means, and control conduit means communicating with and extending radially inward from at least one of said annular passages into said large central opening.

8. A hydraulically driven turntable as defined in claim 7 wherein said port means and said first and second annular passages are defined in said turntable.

9. A hydraulically driven turntable as defined in claim 7 further including a second valve member between said cylinder block and said valving member, said second valve member including said ports and said first and second annular passages.

pockets corresponding in number to said ports, gallery means in said pressure balancing plate for selectively pressurizing alternate ones of said pockets. 

